The present disclosure relates to a semiconductor device. In mobile communication devices, such as cellular phones, to increase the transmission capacity, more and more frequency bands are being used, as seen in the carrier aggregation (CA) technology, for example. This increases the complexity of the circuit configuration of a power amplifier circuit and the subsequent stages, thereby increasing loss in a path from the power amplifier circuit to an antenna. To address this issue, it is desirable to increase output power of the power amplifier circuit.
Daehyun Kang, Daekyu Yu, Kyoungjoon Min, Kichon Han, Jinsung Choi, Dongsu Kim, Boshi Jin, Myoungsu Jun, and Bumman Kim, “A Highly Efficient and Linear Class-AB/F Power Amplifier for Multimode Operation”, IEEE Transactions on Microwave Theory and Techniques, Vol. 56, No. 1, January 2008, p 77-87 discloses a technology of operating a power amplifier by controlling harmonics in the following manner. By short-circuiting second-order harmonics of a transmit signal to a ground and by opening third-order harmonics thereof, the power amplifier is caused to perform class F operation. Class F operation is known as a technique for achieving compatibility between high linearity and high efficiency of a power amplifier.